JP4521895B2 - Solar cell array and photovoltaic power generation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an array configuration used in a photovoltaic power generation system.
[0002]
[Prior art]
In recent years, residential solar power generation systems in which solar cells are installed on the roof and reverse power flow in the commercial power system are becoming widespread. FIG. 3 shows an example of such a grid-connected solar power generation system. An extension cable is connected to each solar cell string, which is a series of a plurality of solar cell modules, connected in parallel in a connection box to form an array, and electric power is supplied to electrical equipment and a commercial system by a grid-connected inverter.
[0003]
As such an array, conventionally, as shown in FIG. 8, the type from which the positive electrode to the negative electrode are straight and not folded, and there is no string end (electrode extraction part) inside the array, the modules are aligned. Is mentioned.
[0004]
However, when this type of string is used, there are restrictions on the installation location and size. That is, a special case is required when a place where the length and width are an integral multiple of that of the module is required, and particularly when various installation forms such as the residential roof illustrated in FIG. 6 can be taken. Not applicable except.
[0005]
Therefore, as shown in FIG. 2, an array having folded strings (modules are not aligned in a straight line) and having a string end (electrode extraction portion) inside the array, folded as shown in FIG. 5 ( The most frequently used type has a string having a folded back such as an array having a string in which the modules are not aligned, and having no string end (electrode extraction portion) inside the array.
[0006]
[Problems to be solved by the invention]
However, in such a type, as shown in FIGS. 2 and 5, the strings are arranged so that adjacent string ends have different polarities. Therefore, as the number of strings increases, the number of extension cables required increases. There was a problem of increasing costs (material costs and construction costs).
[0007]
In addition, before connecting the extension cable, it is difficult to understand how far the string is, and the extension cable is connected to the wrong position. If you make a mistake in the connection position in the middle of the array, it will look like a misplaced button on your clothes, you will not notice until the final voltage check, in which case you will have to rewire the wiring. It takes time and effort.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention comprises a solar cell string formed by connecting a plurality of solar cell modules in series, and an electrode extraction portion of the solar cell string exists in a module other than the outermost peripheral portion of the array. Or a solar cell array in which the solar cell string is folded inside the array and the electric circuit is reciprocated, wherein the solar cell module includes a solar cell element, An output lead wire electrically connected to the solar cell element; a terminal box for each of the positive electrode and the negative electrode disposed on the electrical connection portion of the solar cell element and the output lead wire; and is connected to the distal end, and has a connector which mutually different shapes in the positive electrode for a negative electrode, the electrode extraction portion mutually adjacent strings, same poles Solar cell array that feature that at least one owner where the electrodes were so arranged, a configuration called.
[0009]
In the solar cell array of the present invention, adjacent string end / initial ends have the same polarity. Therefore, parallel connection is possible at that location, and the number of extension cables can be halved. The cable saving effect becomes prominent when such a homopolar arrangement is implemented as much as possible.
[0010]
In addition, since the adjacent strings have the same polarity, the end of the string can be easily distinguished, and the extension cable is unlikely to be erroneously connected.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described specifically and in detail based on embodiments.
[0012]
(An array in which the electrode extraction part of the string has a string that exists in a module other than the outermost peripheral part of the array, and the string is folded inside the array so that the electric circuit is reciprocated)
In this example, the present invention is implemented using a horizontal metal roof building material-integrated solar cell module that is preferably used in a normal private house roof, and the effects thereof are clarified.
[0013]
FIG. 1 is a diagram showing an array of this example, and FIG. 11 is a circuit diagram thereof. On the other hand, FIG. 2 is a diagram showing an array configured by a conventional method, and FIG. 10 is a circuit diagram thereof.
[0014]
As a solar cell module, a horizontal metal roof building material integrated module using a solar cell element having a photoelectric conversion layer formed by depositing a photoelectric conversion layer containing amorphous silicon on a stainless steel substrate (manufactured by Canon, model name) SR2-01) 54 sheets are prepared to form a 9-series 6-parallel array. This module is equipped with a positive and negative terminal box and a connection cable with a connector, so that series connection can be performed very easily. The solar cell module can be modified in various ways including those using an amorphous semiconductor as used in this embodiment and those using crystalline silicon, and such changes are intended by the present invention. Will not be affected.
[0015]
As shown in FIG. 1, in the array of the present invention, adjacent string ends are arranged to have the same polarity. For example, the negative electrode S1- of the string 1 and the negative electrode S2- of the string 2 are adjacent to each other. On the other hand, as shown in FIG. 2, in the conventional array, the adjacent string ends are arranged to have different polarities.
[0016]
As shown in FIG. 11, in the array of the present invention, when connecting an electrode extraction portion at the end of a string and a connection box using an extension cable with a connector, adjacent strings are connected in parallel. The negative electrodes 1 and 2 and the positive electrodes of string 2 and string 3 can be combined into one. For this reason, as shown in FIG. 10, in the conventional method, the number of extension cables is twice the number of strings, that is, twelve, but in this example, only seven are required.
[0017]
However, if the strings are separated from each other, a cable used for parallel connection is required, and the saving effect of the extension cable is reduced. Therefore, it is preferable that the arrays to which the present invention is applied are substantially the same surface.
[0018]
Moreover, in the array of the present invention, it is obvious at a glance where the end of the string is, even if it is not electrically connected. There will be no connection to any other location.
[0019]
In the present invention, adjacent strings are connected in parallel near the end of the string. Normally, in order to connect solar cell strings in parallel, it is necessary to insert a backflow prevention diode for each string. In the present invention, it seems that it is necessary to install a backflow prevention diode on the parallel wiring near the array. However, in fact, only one of the same poles of adjacent strings is connected on the array, and the entire parallel connection is connected via a backflow prevention diode in the connection box as in the past. Such special consideration is unnecessary. In this sense, the parallel connection in the vicinity of the array of the present invention is different from the parallel connection as conventionally performed, and if it is named, it should be called “incomplete parallel connection” or “semi-parallel connection”. belongs to.
[0020]
The array shown in FIG. 1 is led to a connection box with an extension cable, all are connected in parallel in the connection box and connected to an inverter, and the array of the present invention is applied to the grid-connected photovoltaic power generation system shown in FIG. A system is built.
[0021]
(An array in which the strings are folded inside the array and the electrical circuit is reciprocated)
FIG. 4 is a diagram showing an array of this example, and FIG. 5 is a diagram showing an array configured by a conventional method.
[0022]
In this example, the metal roof rod building material integrated solar cell module shown in FIG. 9 was used. As in the previous embodiment, this module also employs a solar cell element using amorphous silicon, and the back metal reinforcing plate has a general roof building material shape. Since the change in the shape of the solar cell module does not affect the idea of the present invention, an object with an aluminum frame may be used. An array consisting of 8 series and 4 parallels was constructed using 32 such modules.
[0023]
In this case as well, as in the previous embodiment, it is clear that the extension cable can be saved and the string end can be easily identified.
[0024]
It should be noted in this example that the strings are folded and wired so that the electrical circuit reciprocates, but there is no string end inside the array and the string end exists only at the array end. is there. In this way, since the electric output unit is gathered at one end, such an installation method is preferably used in many systems.
[0025]
The present invention is also useful when there is a string current collector only at the end of the array as described above.
[0026]
(An array in which a string electrode extraction portion has a string existing in a module other than the outermost peripheral portion of the array)
In this example, an example in which the present invention is applied to a large array that can be installed without folding the string will be described. FIG. 7 is a diagram showing the array of this example.
[0027]
In this example, a string was constructed using a module using crystalline silicon (manufactured by Showa Shell, model name GL136). This module also has a terminal box for each positive and negative, in which the electric wire can be screwed with a crimp terminal. The configuration of the present invention can be realized even if the terminal box is in one box. However, in many cases, the degree of freedom of wiring of the array is increased when they are different. A string was formed by arranging 10 modules in a straight line in the horizontal direction, and nine of them were arranged in parallel to make an array.
[0028]
In the array of the present invention, six string negative electrodes of strings 1, 2, 4, 5, 7, and 8 can be arranged in parallel, and it can be seen that the aim of the present invention is achieved.
[0029]
Note that the string has no wrapping at all. Even if there is no folding, the end of the string exists inside the array, so that the effect of the present invention can be achieved.
[0030]
As described above, the present invention can achieve a substantial effect even with a large array.
[0031]
【The invention's effect】
As described above, the present invention comprises a solar cell string formed by connecting a plurality of solar cell modules in series, and the electrode extraction portion of the solar cell string exists in a module other than the outermost peripheral portion of the array. In the solar cell array in which the solar cell string is folded inside the array and the electric circuit is reciprocated, the electrode extraction parts of adjacent strings have the same polarity. Own at least one place where electrodes are arranged.
[0032]
Accordingly, the end of the string can be easily discriminated even when no electrical connection is made, and as a result, the extension cable is unlikely to be misconnected.
[0033]
In addition, parallelization of strings is possible at the end of the string, and the number of extension cables can be halved. As a result, the number of circuits in the connection box can be reduced and the number of disconnectors etc. can be reduced. Can also reduce costs.
[0034]
Furthermore, since the present invention can be applied even when the string is folded back or the takeout part is inside the array, the array can be installed at various places of installation unlike the conventional method shown in FIG.
[0035]
The industrial utility value of the present invention having such excellent effects is extremely high.
[Brief description of the drawings]
FIG. 1 illustrates an embodiment of an array of the present invention.
FIG. 2 shows a conventional array.
FIG. 3 is an example of a grid-connected solar power generation system.
FIG. 4 shows an embodiment of the array of the present invention.
FIG. 5 shows a conventional array.
FIG. 6 is a view showing a horizontal thatched roof of solar cell modules.
FIG. 7 shows an embodiment of an array of the present invention.
FIG. 8 shows a conventional array.
FIG. 9 is a diagram showing the appearance of the rod-type solar cell module used in the array of FIG.
FIG. 10 is a circuit diagram of the array of FIG.
FIG. 11 is a circuit diagram of the array of FIG.

Claims (5)

A solar cell string composed of a plurality of solar cell modules connected in series, and the electrode extraction portion of the solar cell string has a string that exists in a module other than the outermost peripheral portion of the array, or In the solar cell array in which the solar cell string is folded inside the array and the electric circuit is wired so as to reciprocate,
The solar cell module includes a solar cell element, an output lead wire electrically connected to the solar cell element, and a positive electrode and a negative electrode arranged on an electrical connection portion between the solar cell element and the output lead wire. Each terminal box and a connector connected to the tip of the output lead wire and having different shapes for the positive electrode and the negative electrode,
A solar cell array having at least one place where electrodes of the same polarity are arranged in the electrode extraction portions of adjacent strings.   2. The solar cell array according to claim 1, wherein the number of places where the same polarity electrodes are arranged in the electrode extraction portions of adjacent strings is increased as much as possible. The solar cell array according to claim 1 or 2 , wherein the solar cell module has a back metal reinforcing plate, and the shape thereof is substantially the same as that of a roof building material. A solar power generation system comprising at least the solar cell array according to any one of claims 1 to 3 . 5. The solar power generation according to claim 4 , wherein the solar cell array is installed on a residential roof, has a grid-connected inverter, and can generate a reverse power flow from the solar cell array to the commercial power system. system.

Images